1. Industrial Field of the Invention
The present invention relates to a position detector utilizing electromagnetic induction and its position indicator and especially to a position detector and its position indicator, wherein an inclination of the pen-shaped position indicator and an angle of rotation thereof in the vertical direction in relation to the tablet surface are detected.
2. Prior art
The conventional device of this kind is used for inputting characters and pictures via a pen-shaped position indicator. However, there has been a demand that not only characters and pictures be input in accordance with coordinates but also such factors as angle of a user's arm and rotation and inclination of a pen should also be input as data.
In order to meet such a demand, various kinds of position detectors and position indicators have been developed (for example, Japanese Patent Public Disclosure No. 210450/1993, Japanese Patent Publication Nos. 16506/1983, 1764/1988, Japanese Patent Disclosure No. 67320/1991).
However, the conventional position detectors and position indicators cannot detect an inclination or rotation angle of a pen when the tip of the pen is located on the periphery of an effective area where coordinates on the tablet can be detected.
Furthermore, according to the conventional position detectors and position indicators, a detection coil for detecting an inclination and rotation angle of a position indicator is separately installed in the position indicator and thus, a pen tends to become bulky.